Son of Andrea and Caterina Lengo, on his father’s death in 1826 Cesare Dell’Acqua moved to Capodistria with his mother and brothers. He pursued there his first studies, which he then continued in Trieste from 1833.

He obtained from the commune of Trieste a student grant for the 'Accademia delle Belle Arti' of Venice where he was taught by Ludovico Lipparini, Odorico Politi and Michelangelo Grigoletti.

After a trip to European capitals such as Vienna, Munich and Paris, in 1848 Dell’Acqua went to Brussels where he settled in the home of one of his bothers. There he joined the studio of Louis Gallait, a painter of historical scenes, and in 1855 he married Carolina van der Elst and they had two daughters: Eve and Alina. Even though he lived in Belgium, Dell’Acqua was constantly in touch with the city of Trieste. He painted two large canvases for the Greek Orthodox church in 1852 and 1854: Saint John Preaching in the Desert and Christ and the Little Children. Between 1855 and 1856 he was asked by Baron Pasquale Revoltella to paint two large historical compositions for a room in his Triestine palace: The Proclamation of the Free Port of Trieste and The Dedication of Trieste to the House of Austria, now kept in the Revoltella Civic Museum. After having admired the works by Dell’Acqua bought by his friends Revoltella and Bottacin, Archduke Maximilian of Austria got in touch with the painter when he went to Brussels to marry Princess Charlotte of Belgium. The Archduke commissioned Dell’Acqua to carry out a series of paintings now kept in the historical room of the Castle of Miramare in Trieste. The first two canvases were painted in Brussels between 1857 and 1858 and the other ones were commissioned afterwards. The last two paintings were completed after the death of Maximilian in 1867 but sent to Miramare all the same.

From 1870 the commissions from Belgian clients increased.

Already in 1875, thanks to the fame achieved in Belgium, the commune of Trieste commissioned Dell’Acqua to do a large painting for the town council room. The work, entitled Commercial Prosperity of Trieste, was finished in 1877 and was signed Caesar Dell’Acqua civis tergestinum.

Between 1879 and 1881 the painter received another commission from Trieste: his friend Leopoldo Vianello requested a series of paintings exalting Italian genius for his villa.

In the last two decades of the century Dell’Acqua painted small 'genre' pictures in the Flemish tradition and, at the same time, he continued with his activity as an illustrator.

Cesare Dell’Acqua died in Brussels on February 16th, 1905. At the end of the same year a large exhibition was prepared in the Belgian capital with all the works that were in his study at the time of his death.